The production of static electricity on polymeric materials caused by the accumulation of electrical charge thereon creates problems. Both natural and synthetic polymeric fibers have a tendency to accumulate electrical charge, resulting in the production of static electricity. Numerous methods have been proposed to prevent such electrification. Examples include the application of a surfactant having antistatic properties onto the surfaces of polymeric substrates. The antistatic effects of such surfactants, however, has proven to be only temporary due to their lack of durability, anti-stat properties can be lost during the dyeing process, or during cleaning or by mechanical damage. It has also been proposed that an antistatic agent be incorporated directly into a polymeric substrate during its formation, while at the same time attempting to maintain the fiber's spinnability and quality of construction.
It is common knowledge that fibers prepared from conventional natural and synthetic polymeric materials tend to collect and retain, for periods of time, static electrical charges when coming into contact with each other or foreign objects. The electrostatic charge build-up can occur quite rapidly and often dissipation of the charge into the environmental atmosphere is extremely slow. A consequence of this is that the polymeric material may remain electrostatically charged for hours at a time. This property tends to make filaments difficult to handle during manufacturing operations and results in objectionable fiber properties, particularly in wearing apparel and carpeting. Electrostatically charged polymeric textile materials may not only attract each other, but may also attract such things as dust, dirt, and lint. In general, however, electrostatically charged polymeric substrates, regardless of their form such as, for example, carpeting, plastic packing materials, etc, benefit from dissipation of static charge with respect to their ease of use, appearance and safety.
The accumulation of static charges and the slow dissipation thereof on polyamide fibers prevents finished, polymeric fabrics from draping and wearing in a desirable manner, and causes the same to cling uncomfortably to the body of the person wearing them. Fibers having a high electrostatic susceptibility often cling to guides and rolls in textile machinery during the manufacturing and processing thereof and are sometimes seriously damaged and weakened. As a result, the quality of the end product is lower than it might otherwise be. For these reasons, and because end-uses such as garments, upolstery, hosiery, rugs, blankets and fabrics are greatly benefited by a reduced tendency to accumulate and maintain electrostatic charges, a permanent antistatic composition to be applied thereon is highly desirable.
Presently, in the commercial production of natural and synthetic polymeric fibers, the as-spun filaments are given some treatment to improve their electrostatic and handling properties. This treatment usually consists of passing the filaments, while in the form of a bundle, through a bath or over a wheel coated with a treating of finishing liquid. The finish thus applied is a coating and is not of a permanent nature. Most, if not all, of the antistatic agent on the fiber surface is lost in subsequent processing of the filament by mechanical handling, heating, washing, scouring and dyeing. If the antistatic agent does remain on the fiber until the final end product is produced, it often becomes less effective after the end product is used for a period of time, and especially after a number of washings or dry cleaning operations.
Efforts have been made in the past to produce permanent antistatic polymeric fibers and articles by the application of a more permanent coating. However, due to the harsh finishing applications the coated fibers were subsequently exposed to, the coatings would either be removed and/or fail to perform adequately. It has also been attempted to incorporate antistatic type comonomers directly into the base polymeric materials. For various reasons, however, such as a resulting harsh fiber surface or sacrifice of good fiber physical properties, these methods have been proven unsuccessful.
Antistatic compositions are also used for enhancing the receptivity of plastic surfaces to electrostatically applied coatings, e.g., in automobile production. In this application it is also desirable that the antistatic composition resist removal when exposed to an aqueous rinse or wash liquid.
Accordingly, it is a primary object of the present invention to provide novel compounds capable of dissipating electrical charges.
Another object of the invention is to provide a process for imparting permanent antistatic properties onto natural and synthetic polymeric substrates.